Which symptom would indicate an acute kidney rejection that a renal transplant client should report?

High fever is a significant symptom that should prompt immediate attention in a renal transplant recipient, as it can indicate an acute rejection of the transplanted kidney. An increase in body temperature often signals an immune response, which may occur when the body recognizes the transplanted organ as foreign. This reaction is critical to monitor, as it can lead to serious complications if not addressed promptly.

In this context, other symptoms can arise; for instance, increased urine output may be a normal or healthy sign, particularly in the early stages following a transplant when kidney function is assessed. Severe headaches might be associated with various factors unrelated to kidney rejection, and complaints of weight loss could result from multiple issues, including side effects of medications or changes in appetite.

Therefore, the presence of a high fever specifically aligns with the body's immunologic response to an acute kidney rejection, making it the symptom that should be prioritized and reported by the client.